zlacker

>>qqqqqu+(OP)
Mach's principle. Why is there a "preferred" rotational frame of reference in the universe? Or as stated in this Wikipedia article,

"You are standing in a field looking at the stars. Your arms are resting freely at your side, and you see that the distant stars are not moving. Now start spinning. The stars are whirling around you and your arms are pulled away from your body. Why should your arms be pulled away when the stars are whirling? Why should they be dangling freely when the stars don't move?"

https://en.wikipedia.org/wiki/Mach%27s_principle

>>sam+ol
The two most obvious solutions to the thought experiment presented are either 1) space is absolute in some way (i.e. the classical Newtonian response) or 2) the behavior of space "here" is affected by the by distribution of matter "over there". General relativity gives us a strong argument in favor of (2) by showing that a) many physical principles thought to be absolute are actually relative and b) showing that mass "over there" affects the shape of space "here".

To say anything more concrete requires requires defining the question much more precisely. I believe there is still some disagreement on the interpretation of Mach's principle in light of general relativity. For example, see https://en.wikipedia.org/wiki/Mach's_principle#Variations_in... (and a couple sections above, the 1993 poll of physicists asking: "Is general relativity with appropriate boundary conditions of closure of some kind very Machian?"

I hope that is helpful in some way.